Carl Barus

"[L]et me refer to my original work. Naturally, if a student has been hammering away ever since 1979... he must have accumulated a lot of litter, much of which, perhaps, should have long since been swept away. But the fates are not to be bribed either by pother or importunity. Out of 1,000 men who are called, one (probably the ratio is much smaller) is chosen to do glorious scientific work. The others? Their lot is failure. They may be equally or even more industrious, they may have equal or even greater brain power—the other 999 exist merely to make the illustrious one in whom they culminate, possible. After that, the world will say to each in words of poetic brevity: "The man has done his duty, the man can go." And they do, pretty quickly, to a gentler lethe, flowing between the banks of amaranth and asphodel. Gentlemen, I am one of the 999 about to be forgotten."

"[F]ew important steps in dynamical geology will be made until the methods for the accurate measurement of high temperatures and high pressures have not only been perfected but rendered easily available. On the basis of this conviction the present memoir on high temperatures has been prepared... [I]f the investigation be of any fullness, it is almost essential that the observer master the component parts of his research separately; and not until he has satisfactorily done this can he apply them conjointly."

"[T]he rooms which had been placed at my disposal by the American Museum of New York became temporarily unavailable. ...[W]e determined to rent a house in New Haven, Conn., and thither the laboratory was removed in November, 1882. ...[T]he city offered excellent library and other facilities for scientific work, such as can be met only in the immediate vicinity of a large university [Yale College]. ...The work in New Haven was not satisfactorily completed. In July, 1883, with the appointment of Prof. F. W. Clarke as chief chemist of the Geological Survey, our laboratory was officially connected with the chemical laboratory. Conformably with the further decision of the Director, by which the divers laboratories of the Geological Survey were united in one central laboratory in Washington, it was again necessary to change our basis of operations, this time... from New Haven to Washington. In the quarters assigned to us in the U. S. National Museum, temperature work on so large a scale... appeared impracticable, and it was therefore abandoned. ...In place of the dangerous and cumbersome apparatus of the former laboratory, the endeavor is made to reduce all apparatus to the smallest dimensions compatible with reasonable accuracy of measurement."

"I make... a cursory survey of certain pyro-electric properties of the alloys of . Curiously... the data... led to a striking result.. it appears that the zero resistance f(0), if the resistance at t^O be r = f(t), and the zero coefficient f^{\prime}(0)/f(0), are related to each other by a law which during the stages of low percentage alloying is independent of the ingredients of the alloy, except in so far as they modify its electrical conductivity."

"I develop a method for the direct and expeditious comparison of the thermo-couple with the air thermometer. A comparison of the data... gives me a criterion of the accuracy with which the data in the region of high temperature are known. This indirect method... is not apparently as rigorous as their direct evaluation by means of the air thermometer; but the indirect method requires much smaller quantities of substance and may be conveniently extended to much higher temperatures. Taking all liabilities to error into consideration, its inferior accuracy is only apparent."

"Looking over such famous old books as Montmort's 'Analyse des jeux de hasard' or Moivre's 'Doctrine of Chances' one regrets that so much excellent mathematics should have been wasted on games most of which are wholly obsolete. Coriolus in his '[Théorie Mathématique des Effets du] Jeu de billard' (1835) fared better, for the game is still very much alive and its dynamical terrors unsubdued."

"In even greater measure is this true of the top. The top has been everybody's toy and must, therefore, at one time or another have piqued everybody's curiosity. Lagrange, Poinsot, Jacobi, not to mention other great names, have in turn paid their tribute; yet the top may be set spinning to-day, unhampered by a completed theory to account for its evolutions."

"Among recent contributions we may refer in particular to Professor A. G. Greenhill's noteworthy papers... when one remembers that these complex curves reach only especially simple cases of motion, one may get some notion of the difficulty of the problem involved."

"Turning to Klein's little book, one is astonished in finding the most general aspects of the subject treated almost without computation and in so little space. ...It would have cost little to give the expanded form of the σ-function. ...Weierstrass's original notation was in terms of Abelian functions. The tremendous development of s is out of proportion with their application to natural phenomena. Meeting them rarely one forgets them. Memory peters out like the infinite series of a ζ-function."

"Mathematicians will do well to observe that a reasonable acquaintance with theoretical physics at its present stage of development, to mention only such broad subjects as electricity, elastics, hydrodynamics, etc., is as much as most of us can keep permanently assimilated. It should also be remembered that the step from the formal elegance of theory to the brute arithmetic of the special case is always humiliating, and that this labor usually falls to the lot of the physicist."

"The lecture concludes with a demonstration showing that a free body in hyperbolic non Euclidean space may be so fashioned as in real time to carry out the actual motions of the top. The form of such a body and the forces to actuate it are specified. Klein lays great stress on the beauty of this generalization. ...The full geometry of this case is not carried out in these lectures, however, and Klein regrets that the development of the s has recently fallen into abeyance."

"The reviewer is aware... he has given an imperfect account of this remarkable book. That Klein's researches constitute a splendid advance in dynamics of the rotation of a rigid body there can be no question. One cannot but hope that the outline given in these Princeton lectures may soon be expanded and put in shape more easily assimilated by persons more moderately versed in the theory of elliptic functions."

"The boon of an appropriate lemma is ideal generosity, and not even a mathematician can scorn its almost mathematical elegance."

"A man may be a thoroughgoing soldier enough on land; but put him in the foot ropes of the flying jibboom in a storm, and he is apt to cut a most ludicrous figure. Shift a physicist's foothold of Cartesian differential coordinates, suspend him over an abyss of non-Euclidean space, and he will kick sturdily. Poor policy this, for a missionary!"

"The presiding officer of this [Physics] section was Prof. Carl Barus, who fills the chair of Physics in Brown University. His inaugural address was on "Long Range Temperature and Pressure Variables in Physics." He began by giving a history of the various attempts to provide suitable apparatus for high-temperature measurement. Fusion first played an important part in the manufacture of s, and later those instruments based on specific heat showed an advantage over the fusion instruments. The was referred to as the only fruitful method of absolute pyrometry. The speaker dwelt at length on high-temperature work, the first thorough-going instance of which was by Prinsep in 1829. Then the experiments down to 1887 were considered in detail, and the conclusion reached that the data furnished by the Reichsanstalt will eventually be standard. ...Turning to the applications of pyrometry, he referred to the variation of metallic ebullition with pressure. Results already attained show an effect of pressure regularly more marked as the normal boiling point is higher. Igneous fusion was considered in its relation to pressure and with regard to the solidity of the earth, and the inference was drawn that the interior solidity of the earth, now generally admitted, is due only to superincumbent pressure, withholding fusion. The question of heat conduction was next taken up, and the results deduced by various writers as to the discussed. High pressure measurement was lengthily dealt with. Passing from this subject, the of liquids was considered. ...The paper ended with a reference to isothermals and several kindred subjects."

"In the decade between 1882 and 1892 contributions to gas thermometry and the measurement of high temperatures are few and unimportant, but work was begun in those years on both sides of the Atlantic which, for the experimental skill and persistence with which the experimental difficulties and limitations were pursued and successively overcome, surpasses any effort which has been made either before or since that time. These were the investigations of Barus at the U.S. Geological Survey in Washington and of [Ludwig] Holborn and his colleagues at the Reichsanstalt in Charlottenburg. Barus (1889) recognized as no observer who preceded him had done, the superlative importance of a uniform temperature distribution about the gas thermometer bulb for purposes of high-temperature measurement, and he took the most extraordinary precautions to maintain it. A temperature of 1000° C or more is not attained without very steep temperature gradients in the region immediately surrounding the zone of highest temperature. It is therefore a problem of great difficulty to introduce a bulb of from 10 to 20 cm. in its largest dimension into this hot zone without leaving some portion of it projecting out into a region 200° or 300° lower in temperature. Burning mixtures of gas and air for heating purposes also contributed to the irregularity and uncertainity of the temperature distribution about the bulb. Barus sought to avoid this by a method of great ingenuity, but also of great technical difficulty. He inclosed his bulb within a rapidly revolving muffle which by its motion protected every portion of the bulb from direct exposure to a particularly hot or a particularly cold portion of the adjacent furnace. This complicated furnace structure and consequently inaccessible position of the bulb made it impossible to introduce into the region about the bulb the substances whose temperature constants were to be measured and compelled him to use thermo-elements which were first calibrated by exposure in the furnace with the bulb and then used independently to measure other desired temperatures. The thermo-element has continued in general use in this intermediary rôle since that time. In the preparation and use of thermo-elements Barus also made much more extensive and elaborate studies than any one who has followed him. ...It is an unfortunate accident that history has failed to record Barus's name along with that of Le Chatelier in the development of the thermo-element for purposes of high-temperature measurement. It hardly admits of question that Barus contributed incomparably more to our knowledge of the thermo-electric properties of the different metals and their use than his distinguished French contemporary, but the 10 per cent iridium alloy which he finally selected proved to be less serviceable than the 10 per cent rhodium alloy developed by Le Chatelier... And so we find the Le Chatelier platin-rhodium thermo-element in use to-day the world over, while the magnificent pioneer work of Barus remains but little known."

"[T]he author, whose work on nuclei is well known, describes a number of investigations carried out with his fog-chamber apparatus. The apparatus having been sufficiently improved, it was used for various experiments, including the growth of persistent nuclei, the production of water nuclei by evaporation, the results obtained when X-rays are allowed to strike the fog-chamber from different distances, the effect due to radium, &c. Other problems dealt with in the book are the distribution of colloidal nuclei and of ions in media other than air-water, the simultaneous variation of the nucleation and the ionization of the atmosphere of Providence, and the variations of the colloidal nucleation of dust-free air in course of time."

"When the history of the progress of physics in the United States during the late nineteenth and early twentieth century is written, the name of Carl Barus will occupy an important place."

"At Brown University Carl Barus and Alpheus Packard are undoubtedly the most eminent scientists who ever occupied faculty chairs. Professor Barus was a hero-worshipper and in his home was a genius corner from which pictured faces of great scientists looked down upon him. ...The breadth of his interest and achievements was extraordinar—recall his reading of Greek tradedies in the original, his knowledge of French and Italian literatures, and the proficiency he attained in playing the violin, flute, clarinet, oboe, cornet, trumpet and trombone, in addition to the piano and organ. The brilliancy of his intellect, the modesty of his bearing, the beauty of his personality, and the kindliness of his spirit have left most precious and inspiring memories..."

"Carl Barus loved music, and composed about fifty compositions, among them a March to Pembrok Hall... and an Ode to the Steam Shovel, inspired by the daily noise outside his laboratory and was presented by him to President Faunce."